Method for making connectors with hard particle lining



Feb- 10, 1953 1. F. MATTHYssE 2,627,549

NNNNNN 0R Patented Feb. 10, 1953 METHOD FOR MAKING CONNECTORS WITH HARD PARTICLE LINING lrvng F. Matthysse, New York, N. Y., assigner to Burndy Engineering Company, Inc., a corporavtion of New York @riginal application August 7, 1948, Serial No. 43,023, now Patent No. 2,57 6,528, dated Novem ber 27, 1951. Divided and this application April 5, 1950, Serial No. 154,069

(Cl. 21B-148) 4 Claims.

My invention relates to a method for inakng connectors having tubular bodies that may be used to splice wires or cables, and more par* ticularly to the types that are indented to the wire and locked thereto by hard particles that key the connector to the wire. This application is a division of my applicsnaion,l Serial No. 43,023 led August 7, 1948, now Patent No. 2,576,528.

Hitherto, inV actual practice, such devices have employed chromium, Nichrome crimen-metallic particles applied to the inside surface of the tubular connector, asis illustrated in Patent No. 2,149,209. These particles produce unsatisfactory results, wherethe connector is used to transmit current or Where the metal of the particles is different from that of the connector or wire, for 4in the first case chromium, Nchrome and hardnon-metallic particles are highly resistant to the flow of current, and in the latter case electrolytic corrosion may set in.

Accordingly, the primary object of my invention is to provide a method of applying and treating a suitable keying-in material that may be secured to the inside of a hollow connector to form a lining which will more nearly approach the conductivity of the metal forming the connector body, than particles previously used for this purpose, and which additionally will not cause electrolytic corrosion.

I have found that I can solve the problem of conductivity and electrolytic corrosion when copper connectors and wires are employed by alloying copper with a small amount of beryllium. Unfortunately the alloy when sprayed does not harden sufficiently to warrant extensive use as a keying material. Since the aforesaid alloy may be made exceptionally hard,` another object of my invention resides in providing a method of hardening the particles secured to the inside of tubular connectors.

Copper connectors of the 'Splicing type are considerably worked during the manufacturing process, and indention of the connector walls for securing the connector to a wire requires readily malleable material. This can be accomplished by heating and annealing the copper connector thereby softening the walls.

A still furtherl object'consists in providing a method whereby the connector body can be softcned and the alloy particles hardened.

I have further discovered that by applying the molten alloy inside the connector walls, that I can thereafter harden the alloy and soften the connector walls in one operation by simultaneously heating the connector with the alloy particle lining.

fil.

Other objects consist in providing methods of applying the alloy particles to the connectorin a manner which will be least expensive, and readily adaptable to mass production methods.

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specincation, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

Fig. 1 is a side elevation of a connector splice having an inner particle lining made in accordance with my invention.'

Fig. 2 is an enlarged cross sectional view taken in the plane 2 2 of Fig. 1.

Fig. 3 is a side elevation, partly in section of my connector splice secured to a conductor.

Fig. 4 is a cross-sectional view of the same taken in the plane 4-4 of Fig. 3, showing the indenting dies in position.

Fig. 5 is an enlarged longitudinally sectioned and fragmentary view of the connector wall to which the particle lining has been secured with the conductor in position, and before identation.

Fig. 6 is a similar view after indentation.

In the drawings, reference numeral Ill designates a tubular body or sleeve having an internal hard particle lining Il. The diameter of the internal bore of the sleeve must be suicient for clearance over the wire l2, allowing for the thickness of the particle lining. The wire stops I3 and I4 may be formed in the bore to prevent inserting` the wire too far, by indenting the sleeve as at I5. Each entrance I 6. to the inside of the sleeve is well chamiered or rounded as at l1, to prevent nickng the wire and to prevent breakage due to possible vibration. The chamfer lT-a on the outside is to prevent snagging when the wire and sleeve are pulled over a cross-arm of a pole.

The compressed portions or indents i8, are produced by compressing dies IB and 20. shown in Fig. 4, which may leave a small ash 2|. As a result of these indehtations the surface of the wire takes on a wavyiorni as seen at Fis. 3, thereby increasing the grip of the sleeve on the wire,

In Figure 5, there is illustrated an enlargement of a portion of a longitudinal section of the sleeve with thev Wire inserted in place. The particles are preferably .formed with. sharp points indi` cated by the roughness of the liner Il, on the sleeve It. Both the inside of the sleeve 23, and the outside of the wire 24, may be smooth. The hard particles forming the liner are secured to the inside wall by a number of methods hereinafter explained. After compression this enlarged longitudinal section appears as in Figure 6, in which the individual hard particles 25, are seen to have impressed themselves into the softer surfaces of the sleeve and wire, each particle preferably acting as a key to prevent any slipping of the wire relative to the sleeve under longitudinal tension. Thus with a suitable arrangement of indentations each having the proper amount of compression or depth, the wire will not slip under tension, and will fail only when the ultimate streng-th of the wire is approached and preferably outside the connection.

Particles made of copper containing from 1% to 2%% of beryllium is satisfactory. I have found that 98% copper and 2% beryllium is preferred and that an excess of 2% of beryllium does not materially add to the hardness of the alloy to justify the expense of the added quantity of beryllium and Will lower the current carrying capacity of the alloy. The 2% alloy has a current carrying capacity, for equal temperatures, of approximately one-half that of purecopper and approximately equal to the current carrying capacity of materials customarily used to make electrical connectors. On the other hand, the 2% beryllium-copper alloy h-as an electrical conductivity of over fifteen times that of Nichrome, now used as a particle lining.A The 2% beryllium-copper alloy has a Rockwell hardness of N 72 compared with l5 N 40, the Rockwell hardness of hard drawn,A copper wire. Thus the alloy particles will penetrate copper Wires and, of course, the much softer pure copper, Without diculty. Irregular and pointed particles suitable for a sleeve liner may be obtained from this material by spraying the molten alloy with a conventional metal spraying gun and directing this spray into the barrel of the connector sleeve causing the particles to adhere when they strike the inner surface of the sleeve. Thereafter the particle lining is treated by a heat treating process which simultaneously increases the hardness ofthe lining While annealing the copper sleeve to the correct degree of malleability. A'suitable temperature is approximately 650 F., held for about one hour, and cooled slowly thereafter.

Another method of applying the particles to the inside of a sleeve consists in coating thereon a thermosetting material such as a silicon resin or any suitable thermo-plastic adhesive. In such method the particlesmay be applied to the coated surface of the sleeve,.and the combined sleeve, adhesve, land particles heat treated as aforesaid. Thus, in the latter case the adhesive may be softened under the heat While in the former case it is hardenedby the heat while the particles are in contact therewith, thus retaining the particles When cooled. v l

' Still another method comprisesa novel process for manufacturing particlesv of the proper size and shape, and hardening them While in their loose form. This can be accomplished by spraying the molten alloy into cold Water after which the particles may be collected, and sorted by sieving to obtain the desired range of particle size. The particles may then` be hardened by the aforementioned heat-treatment, and applied to the inner surface of the sleeve. This may be advantageous Where it is desired to heat the sleeve to a different temperature than that needed to harden the particles.

It will be thus seen that by hardening the keying particles after they are formed, the process of making particles and the materials for them need not be restricted to those processes and materials which produce hard particles.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways Without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of Which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

l. In the Vmethod of manufacturing an electrical connector sleeve made of copper tubing requiring heating to soften the same to render it readily malleable for indenting to a hard copper conductor, the steps of forming on the inner surface of the sleeve a coating containing sprayed beryllium copper particles, and heating to anneal the sleeve and to harden the particles for use as a keying materia1 when the connector is indented to the conductor.

2. In the method of claim 1 thesteps of applying the coating in the form of an adhesive which is softened by heat, applying the particles to the coating, and heating the sleeve, adhesive and particles to soften the sleeveand adhesive and to hardenthe particles. K y

3. In the method of claim 1 the steps of applying the coating in the form of an adhesive which is hardened by heat, applying the particles to the coating, and heating the sleeve, adhesive and particles to sof-ten the sleeve, and to harden the adhesive and particles.

4. In the method of cl-aim 1, the step of adding beryllium copper particles containing approximately 2% of beryllium.

IRVING F. MATTHYSSE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,898,487 Hurley Feb. 21, 1933 1,936,185 Brenizer Nov. 2l, 1933 2,038,535 Brenizer 'Apr.28, 1936 2,149,209 Dickie et al Feb. 28, 1939 2,178,529 Calkins Oct. 31, 1939 2,206,652 Conradi July 2, 1940 2,244,109 Klein June 3, 1941 2,254,516l Farr Sept. 2, 1941 2,474,038 Davignon i June 2l, 1949 2,490,543 Robertson et al Dec. 6, 1949 2,576,528 Matthysse 1 Nov. 27, 1951 

1. IN THE METHOD OF MANUFACTURING AN ELECTRICAL CONNECTOR SLEEVE MADE OF COPPER TUBING REQUIRING HEATING TO SOFTEN THE SAME TO RENDER IT READILY MALLEABLE FOR INDENTING TO A HARD COPPER CONDUCTOR, THE STEPS OF FORMING ON THE INNER SURFACE OF THE SLEEVE A COATING CONTAINING SPRAYED BERYLLIUM COPPER PARTICLES, AND HEATING TO ANNEAL THE SLEEVE AND TO HARDENED THE PARTICLES FOR USE AS A KEYING MATERIAL WHEN THE CONNECTOR IS INDENTED TO THE CONDUCTOR. 